feat(run-script): soft-depend on add-script to enforce install order

[Copilot]

When both add-script and run-script are used together, there's no guarantee add-script is installed first. Adding it as a soft dependency via installsAfter ensures correct ordering without forcing add-script to be installed when only run-script is used.

Changes

• src/run-script/devcontainer-feature.json — added add-script to installsAfter; bumped version 1.1.2 → 1.2.0
• README.md — updated run-script version in the feature table

"installsAfter": [
    "ghcr.io/devcontainer-community/devcontainer-features/ca-certificates:latest",
    "ghcr.io/devcontainer-community/devcontainer-features/add-script:latest"
]

installsAfter is a soft dependency: the ordering is enforced only when both features are present in a user's devcontainer.json.

Original prompt

For feature "run-script", make sure the feature "add-script" is always installed before "run-script". Also make sure "add-script" is NOT a hard dependency of "run-script".

In other words: if a user installs both, run-script, and add-script, then add-script should always be installed first.

If a user only installs run-script, add-script should not be installed.

For changes that you make to achieve this, bump minor version of the feature.